The electrical systems of motor vehicles are steadily increasing in complexity. A typical motor vehicle includes a large number of relatively low horsepower motors for activating its various systems and accessories. Motor vehicles now often include relatively sophisticated sound systems, radio telephone equipment and microprocessor based controllers. The interaction of these various components can present a problem, since electric motors can generate significant amounts of electromagnetic noise, which may interfere with the operation of other components in the vehicle. As a consequence, radio frequency noise suppression circuitry is frequently included in motor vehicles. As is known in the art, circuits of this type typically include one or more choke coils which act to inductively limit the passage of high frequency electromagnetic signals therethrough. Also, the circuitry frequently includes one or more capacitors disposed so as to pass high frequency signals to ground, while blocking the passage of low frequency or direct current signals. Since even a relatively short length of an electrical conductor can act as an antenna for broadcasting electromagnetic noise throughout a motor vehicle, it is preferred that noise suppression circuitry be disposed as close as possible to the source responsible for the noise. Various noise suppression systems are known in the prior art. For example, U.S. Pat. No. 4,845,393 discloses an end cap for a fuel pump which includes integral noise suppression circuitry. U.S. Pat. No. 4,819,130 discloses an add on noise suppressor which can be installed onto an ignition coil.
The present invention is directed to a noise suppression system which is an integral part of a motor brush support assembly. The system of the present invention is rugged, reliable and easy to fabricate. It is configured so that all parts requiring precise mechanical tolerances are supported on a single, base portion so as to facilitate the maintenance of precise tolerancing. As will be described in greater detail hereinbelow, it may be used in combination with a number of standardly configured motors. Furthermore, the various components of the present invention are readily manufactured by straight pull molding, and can function as receivers for retaining and directing the assembly of remaining portions of the system. These and other advantages of the invention will be apparent from the drawings, discussion and description which follow.